Global trends in phytoplankton research of river ecosystems during 1991–2016: A bibliometric analysis

Rivers are representative lotic freshwater ecosystems and are regarded as the lotic belt for transportation of nutrients and pollutants from the land to the sea. To understand the global research profile and fronts of river phytoplankton, 13,434 publications regarding river phytoplankton indexed by Web of Science during 1991-2016 were analyzed using a bibliometric approach. The EU Water Framework Directive presents a good case for promoting not only frequent cooperation between European countries but also the development of river phytoplankton studies. Such directives are anticipated to promote global consistency of the water evaluations and management in the future. Phytoplankton play important roles in bio-assessments and energy flow of river ecosystems. The trait-based method has many advantages compared with traditional methods based on community composition and metric indices. The trait-based method considers a complex mixture of stressors by combining qualitative and quantitative parameters but also transfers different geographic taxonomic compositions to a similar complement of traits. Moreover, phytoplankton-based food chains are generally considered to transfer energy and carbon more efficiently to higher trophic levels than bacterial-based food chains. Algae are a high-quality food for higher trophic levels, compared with bacteria and terrestrial material. The algal component of periphyton has been demonstrated to be the major basal component of stream food webs.